[DocHoliday]

I may buy another ZS6 in a few weeks when everyone blows through some current stock so I can get the new ones.

IMO, IT03's have the better sound signature, but the IT03's don't have the low extension and don't have the bass response to really carry EDM. Sub bass is definitely up 3-5dB on the ZS5's which makes for a good amount of lows while not really overpowering anything. I also find the soundstage surprisingly narrow and lackluster compared to the ZS5's. I also notice everything in the soundstage is backwards and I've noticed this on serveral KZ IEM's. Things that flow to the left in the ZS5's, flow to the right in the IT03's. The IT03's have what seems to be the more accurate 3D placement due to my previous sentence, but it's just not as wide or big as the ZS5's. IT03's have finer details, but most of what you hear is compression artifacts on absolutely everything except lossless formats.

Fit: Keep in mind I'm a female, so YMMV. IT03 is poor with fit, providing really poor quality tips that are simply unacceptable for $259. I had one slip off the nozzle and get stuck in my ear earlier. I had to get a friend to pull it out with tweezers at work. They don't fit on the nozzle and they aren't great in the ear.

Value on these IT03's is absolutely embarrassing. KZ can give me a better quality cable and tips for $27, including the IEM's. I wouldn't pay more than $79.99 for them and I feel like that's a steep asking when KZ can provide similar IEM's made of metal with an extra DD for $45. If this is what the audiophile world looks like - subpar sound that's only made good by marketing and class status, I'm going to keep buying the cheap chi-fi IEM's that sound just as good.

I bet the big [predatory marketing] companies feel really threatened by KZ.

*Disclaimer: I am not paid by KZ or iBasso, I have never received any IEM's for free or for review. All were bought with personal money and these are the opinions of myself.

Still finishing my final review on my website, will have it up by Monday/Tuesday.

I have to say, I think your on to something here, khighly!

============================

"I may buy another ZS6 in a few weeks when everyone blows through
some current stock so I can get the new ones."

I was going to suggest this to you but I didn't want to be presumptuous. The ZS6 is just too good an IEM to not have in your collection. I still think maybe one of these days you can find a matching earpiece from a community member in the future. Just a matter of time.

****************************

"IMO, IT03's have the better sound signature, but the IT03's don't have the
low extension and don't have the bass response to really carry EDM.
Sub bass is definitely up 3-5dB on the ZS5's which makes for a good amount
of lows while not really overpowering anything."

Again, color me surprised, but so be it! This serves as a reminder that multiple reviews are necessary to gain a clearer picture. Every other review says the bass is one of the defining characteristics of the IT03 giving me the impression that the IT03 borders on being a basshead IEM. I'm glad you weighed in with an opposing voice if it's not what your hearing, especially if your not hearing that bass when the IT03 is coupled to your Magni 3.

****************************

"I also find the soundstage surprisingly narrow and lackluster compared
to the ZS5's. I also notice everything in the soundstage is backwards and
I've noticed this on serveral KZ IEM's. Things that flow to the left in the ZS5's,
flow to the right in the IT03's. The IT03's have what seems to be the more
accurate 3D placement due to my previous sentence, but it's just not as wide
or big as the ZS5's."

That's the most interesting thing I've heard this year (reversed soundstage/imaging). I'll have to go through my collection because I've never picked up on this before. You've definitely piqued my interest here.

****************************

"IT03's have finer details, but most of what you hear is compression artifacts
on absolutely everything except lossless formats."

So it appears that the IT03 is very transparent, though I don't want to put words in your mouth.

****************************

"Fit: Keep in mind I'm a female, so YMMV. IT03 is poor with fit, providing really poor quality tips that are simply unacceptable for $259. I had one slip off the nozzle and get stuck in my ear earlier. I had to get a friend to pull it out with tweezers at work. They don't fit on the nozzle and they aren't great in the ear."

Ya know.....I have to say that this is where the rubber meets the road and why I am a self-proclaimed fan of Knowledge Zenith. KZ screws up or p****s me off from time to time, but there is no question that they offer huge value for my money. HUGE! At $260 the IT03 should not be skimping on $1 eartips and $15 cables. Every $12.99 detachable cable available for the KZ lineup is better than the detachable cables included with the IT03. That speaks volumes about how iBasso views their target customer. For crying out loud "good IEMs with crappy cables and crappy eartips" is how many of us would describe Chi-Fi in the sub-$20 realm. I know the whole "pricing tier" thing, but there is no way to justify crappy eartips and cables when they could have easily sourced decent eartips from sellers who "LIST" decent cables and eartips for 99 cents and $12.99, respectively,
AND THE SELLER STILL HAS HIS PROFIT BUILT IN TO THAT PRICE.
Shameful, just shameful.

****************************

"Value on these IT03's is absolutely embarrassing. KZ can give me a better quality cable and tips for $27, including the IEM's. I wouldn't pay more than $79.99 for them and I feel like that's a steep asking when KZ can provide similar IEM's made of metal with an extra DD for $45. If this is what the audiophile world looks like - subpar sound that's only made good by marketing and class status, I'm going to keep buying the cheap chi-fi IEM's that sound just as good.

Here, here.......all in favor say Aye!

AYE!

****************************

I bet the big [predatory marketing] companies feel really threatened by KZ.

*Disclaimer: I am not paid by KZ or iBasso, I have never received any IEM's for free or for review. All were bought with personal money and these are the opinions of myself.

Still finishing my final review on my website, will have it up by Monday/Tuesday.

Good girl (don't mean that in a condescending way)
Good input
Food for thought when considering what to buy and weighing what one gets.

For less than $100 you can obtain the following and be very, very happy.

'Nuff said .......drops the mic.....walks away.

 

[nkramer]

After my first set of Comply foams, I said "never again." I will not pay that kind of money for ten cents worth of foam. Not when they arrive looking this (right side of pic).

i haven't tried that style yet, or had any arrive misshapen. the only ones i've ever bought were the normal shape in a couple different sizes (T-100, T-200) & colors.

 

[nkramer]

but like i said, i am excited to try the inexpensive new bee ones, when i need to order some more.

 

[khighly]

I have to say, I think your on to something here, khighly!

============================

"I may buy another ZS6 in a few weeks when everyone blows through
some current stock so I can get the new ones."

I was going to suggest this to you but I didn't want to be presumptuous. The ZS6 is just too good an IEM to not have in your collection. I still think maybe one of these days you can find a matching earpiece from a community member in the future. Just a matter of time.

****************************

"IMO, IT03's have the better sound signature, but the IT03's don't have the
low extension and don't have the bass response to really carry EDM.
Sub bass is definitely up 3-5dB on the ZS5's which makes for a good amount
of lows while not really overpowering anything."

Again, color me surprised, but so be it! This serves as a reminder that multiple reviews are necessary to gain a clearer picture. Every other review says the bass is one of the defining characteristics of the IT03 giving me the impression that the IT03 borders on being a basshead IEM. I'm glad you weighed in with an opposing voice if it's not what your hearing, especially if your not hearing that bass when the IT03 is coupled to your Magni 3.

****************************

"I also find the soundstage surprisingly narrow and lackluster compared
to the ZS5's. I also notice everything in the soundstage is backwards and
I've noticed this on serveral KZ IEM's. Things that flow to the left in the ZS5's,
flow to the right in the IT03's. The IT03's have what seems to be the more
accurate 3D placement due to my previous sentence, but it's just not as wide
or big as the ZS5's."

That's the most interesting thing I've heard this year (reversed soundstage/imaging). I'll have to go through my collection because I've never picked up on this before. You've definitely piqued my interest here.

****************************

"IT03's have finer details, but most of what you hear is compression artifacts
on absolutely everything except lossless formats."

So it appears that the IT03 is very transparent, though I don't want to put words in your mouth.

****************************

"Fit: Keep in mind I'm a female, so YMMV. IT03 is poor with fit, providing really poor quality tips that are simply unacceptable for $259. I had one slip off the nozzle and get stuck in my ear earlier. I had to get a friend to pull it out with tweezers at work. They don't fit on the nozzle and they aren't great in the ear."

Ya know.....I have to say that this is where the rubber meets the road and why I am a self-proclaimed fan of Knowledge Zenith. KZ screws up or p****s me off from time to time, but there is no question that they offer huge value for my money. HUGE! At $260 the IT03 should not be skimping on $1 eartips and $15 cables. Every $12.99 detachable cable available for the KZ lineup is better than the detachable cables included with the IT03. That speaks volumes about how iBasso views their target customer. For crying out loud "good IEMs with crappy cables and crappy eartips" is how many of us would describe Chi-Fi in the sub-$20 realm. I know the whole "pricing tier" thing, but there is no way to justify crappy eartips and cables when they could have easily sourced decent eartips from sellers who "LIST" decent cables and eartips for 99 cents and $12.99, respectively,
AND THE SELLER STILL HAS HIS PROFIT BUILT IN TO THAT PRICE.
Shameful, just shameful.

****************************

"Value on these IT03's is absolutely embarrassing. KZ can give me a better quality cable and tips for $27, including the IEM's. I wouldn't pay more than $79.99 for them and I feel like that's a steep asking when KZ can provide similar IEM's made of metal with an extra DD for $45. If this is what the audiophile world looks like - subpar sound that's only made good by marketing and class status, I'm going to keep buying the cheap chi-fi IEM's that sound just as good.

Here, here.......all in favor say Aye!

AYE!

****************************

I bet the big [predatory marketing] companies feel really threatened by KZ.

*Disclaimer: I am not paid by KZ or iBasso, I have never received any IEM's for free or for review. All were bought with personal money and these are the opinions of myself.

Still finishing my final review on my website, will have it up by Monday/Tuesday.

Good girl (don't mean that in a condescending way)
Good input
Food for thought when considering what to buy and weighing what one gets.

For less than $100 you can obtain the following and be very, very happy.

I think you're giving them too much credit on that cable. It has to be no more than $3, and the ear tips can't be more than $1. I wouldn't be surprised if they spent more on the box and awful leather "carrying case" than the cable. It seems like deceiving customers with marketing nonsense like "high purity copper infused with 100% purity nitrogen" can get the people who actually buy these to ignore the physical build quality of the cable itself and endlessly push that it isn't a bad cable.

They sound fine, don't get me wrong, this is more of a complaint about accessories and build quality.

The Soundstage/Imaging reversal in KZ's I've posted about awhile ago as well, maybe 8-10 months. Everything sits BEHIND me in the KZ's, but any other IEM it sits in front of me. There's an EDM song I listen to where it has this loud "slap" sound and it cracks like a whip -- In the ZS5's it goes right to left, in the IT03's it goes left to right.

The IT03 thread should be fun to watch.

 

[maxxevv]

In the ZS5's it goes right to left, in the IT03's it goes left to right.

There is the possibility that the cable has been wired/ labeled L/R opposed. Perhaps you can try and see if you get the correct stereo effect by swapping the left and right connections?

 

[vladstef]

I may buy another ZS6 in a few weeks when everyone blows through some current stock so I can get the new ones.

IMO, IT03's have the better sound signature, but the IT03's don't have the low extension and don't have the bass response to really carry EDM. Sub bass is definitely up 3-5dB on the ZS5's which makes for a good amount of lows while not really overpowering anything. I also find the soundstage surprisingly narrow and lackluster compared to the ZS5's. I also notice everything in the soundstage is backwards and I've noticed this on serveral KZ IEM's. Things that flow to the left in the ZS5's, flow to the right in the IT03's. The IT03's have what seems to be the more accurate 3D placement due to my previous sentence, but it's just not as wide or big as the ZS5's. IT03's have finer details, but most of what you hear is compression artifacts on absolutely everything except lossless formats.

Fit: Keep in mind I'm a female, so YMMV. IT03 is poor with fit, providing really poor quality tips that are simply unacceptable for $259. I had one slip off the nozzle and get stuck in my ear earlier. I had to get a friend to pull it out with tweezers at work. They don't fit on the nozzle and they aren't great in the ear.

Value on these IT03's is absolutely embarrassing. KZ can give me a better quality cable and tips for $27, including the IEM's. I wouldn't pay more than $79.99 for them and I feel like that's a steep asking when KZ can provide similar IEM's made of metal with an extra DD for $45. If this is what the audiophile world looks like - subpar sound that's only made good by marketing and class status, I'm going to keep buying the cheap chi-fi IEM's that sound just as good.

I bet the big [predatory marketing] companies feel really threatened by KZ.

*Disclaimer: I am not paid by KZ or iBasso, I have never received any IEM's for free or for review. All were bought with personal money and these are the opinions of myself.

Still finishing my final review on my website, will have it up by Monday/Tuesday.

It's quite brave saying this about critically acclaimed IEMs and I believe that you are probably mostly right. There is a thing though that you need to figure out, talking about sounds going left - right. I've never had this sort of issue, with every song that I am used to, I can pinpoint and expect specific sounds to come from either left or right and the only thing that varies between IEMs is how far stuff is (also depth, the way sound envelops your head, how precisely defined it is in space - but it's irrelevant for this conversation). Maybe it's polarity issue or something, maybe channel imbalance?

For the longest time I've been questioning everything about pricing in IEM industry because of an example - I had original Sennheiser IE800 for about a year and got really used to everything that it brings to the table. Going from it to ZS5v1 didn't exactly feel like I lost a whole world of sounds like price would suggest. Yes, you lose some but we are talking percentages here. On the other hand, ie800 and ZS5 (which have kinda similar tonality) were never even close to what I prefer and currently I am enjoying TinAudio T2 more than I ever did these other two.

It's a shame that companies got away with charging thousands of dollars for IEMs which have drivers that cost dozens of dollars maximum. Ok, there is R&D and some for profit, but this industry took it further than what Apple does with their products and audiophile community mostly accepts it.

 

[Podster]

Definitely jealous! Always wanted the ZN1 with the amp just for the novelty of them.

......and what have we here? An old skool KZ that is STILL UNOPENED in the plastic.

Talk about a treasure chest!

...and those ED11s......talk about rare! I think those are my favorite of the bunch.

If you say you have the ANV and the Micro-Rings then I'll get my binky and blanky .........and sulk.

I've always said that if you see one really beautiful woman at some point in your day then you can consider that a good day,

......but those KZ's sure are headturners.

Thanks for the trip down memory lane, Pod! Much appreciated! Much!

Speaking of memory lane...... pick a KZ....... plug them in....... and enjoy.....

THX for the Stones Doc, I'm a fan and just got the clear vinyl Hot Rocks set to go with my Red vinyl Sticky Fingers Don't have the ANV's but I do have my MRings stashed somewhere, probably the same place I have the 11's or BrassBack 10's as I call them
That is my backup pair of 11's in the unopened shield The ZN1's are with my Die Cast collection, every once in a while I'll bring them out and test them with a new budget DAP but like Slaters pair I could tell they are delicate so i've really babied them. They really enhance the Mrobo C5, sounds more like my Benjie S5 with the Mini amp

 

[Slater]

There is the possibility that the cable has been wired/ labeled L/R opposed. Perhaps you can try and see if you get the correct stereo effect by swapping the left and right connections?

That's what I was just going to say. But @khighly said she's "noticed this on serveral KZ IEM's", which would be very odd if numerous cables were 1. wired incorrectly or 2. plugged in wrong.

Like @DocHoliday, I'm definitely going to be looking into this with interest as well.

@khighly, you mentioned an EDM song with whip as an example of this anomaly. Would you mind telling us the artist/title so I can check it on my gear?

 

[durwood]

I gotta say y'all, the New Bee and other knockoff foams kinda do the job, but real Complys are the absolute t*ts. I was 100% on team, "I'm not paying $5 a pair for eartips," BUT a set came with one of my recent IEM purchases and they're so good that I picked some up for my ZS6s and my A4s (which both conveniently take T400s). The upgrade is personally completely worth the price premium. SO so much longer rebound for a better, more comfortable seal with deeper insertion.

Bummer, way to ruin it for me. Been using complys since I found out about them, silicones just don't jive with me either. I really also wanted to hope the generics would be equivalents. I am sure they will work, I guess a few bucks is not terrible to find out how they compare to the complys I have.

Try them with the KZ Starline tips (ie ZS5, ZS6 tips). They are an improvement over the ZS3 tips (at least with me).

Will do.

Also, if you swap the stock mesh with standard stainless mesh, it makes an improvement to the treble and will decrease the boomy subbass.

I removed the foam to see, after almost mangling my ZS5 mesh trying to get it back on the ZS5 not sure I want to bother. I might just let these live as is.

As far as the amount of treble, they definitely don't have the 10k spike that the ZS5v3 and ZS6 do - those have 2 ultra-high frequency BA drivers blasting into your eardrum like laser beams. But the CM5 has a decent amount of bright sparkly treble that I think is balanced compared to the rest of the frequencies.

At higher volumes the CM5 do sound more balanced. I like the ZS5v2 at low volume, but the CM5 at low volume doesn't really come alive.

That's my impression, too. And although the CM5 is slightly warmer that the ZS6, I don't find them dark.

Ok, I hate subjective words so you got me there. Let's put it into comparison with some pics. I was wrong about the ZS3, I think because of the midbass hump it appears to have less sub bass.

Disclaimer: Only did these for comparison, my imm6 cal file is loaded but I have not done any other compensation. I really should fire up a laptop with Arta instead of my Samsung S3.

Graph 1 (White = ZS3 foam removed vs purple = Uiisii CM5) Graph 2 (White=UiiSii CM5 vs Purple= ZS5v2)

 

[khighly]

That's what I was just going to say. But @khighly said she's "noticed this on serveral KZ IEM's", which would be very odd if numerous cables were 1. wired incorrectly or 2. plugged in wrong.

Like @DocHoliday, I'm definitely going to be looking into this with interest as well.

@khighly, you mentioned an EDM song with whip as an example of this anomaly. Would you mind telling us the artist/title so I can check it on my gear?

I'm working overtime tonight, so I may not be able to post it tonight, but I put a reminder in my phone to post it tomorrow.

I've done balance tests and verified that all of my KZ's are working properly

 

[khighly]

It's quite brave saying this about critically acclaimed IEMs and I believe that you are probably mostly right. There is a thing though that you need to figure out, talking about sounds going left - right. I've never had this sort of issue, with every song that I am used to, I can pinpoint and expect specific sounds to come from either left or right and the only thing that varies between IEMs is how far stuff is (also depth, the way sound envelops your head, how precisely defined it is in space - but it's irrelevant for this conversation). Maybe it's polarity issue or something, maybe channel imbalance?

For the longest time I've been questioning everything about pricing in IEM industry because of an example - I had original Sennheiser IE800 for about a year and got really used to everything that it brings to the table. Going from it to ZS5v1 didn't exactly feel like I lost a whole world of sounds like price would suggest. Yes, you lose some but we are talking percentages here. On the other hand, ie800 and ZS5 (which have kinda similar tonality) were never even close to what I prefer and currently I am enjoying TinAudio T2 more than I ever did these other two.

It's a shame that companies got away with charging thousands of dollars for IEMs which have drivers that cost dozens of dollars maximum. Ok, there is R&D and some for profit, but this industry took it further than what Apple does with their products and audiophile community mostly accepts it.

I knew it was too good to be true. Sure maybe you'll get better build quality, better isolation, a better warranty, and better quality control, I'm not dismissing those -- but it really seems like there are diminishing returns and I know if I dropped $1100 on a CA IEM I'd likely end up disappointed, especially after reading reviews on the IT03's where they compare them to CA Andromeda's.

The point I'm trying to make here is that you don't need a $200, $300, $1200 IEM to get a pleasant well respected sound. You can have many $10-$40 Chi-Fi IEM's, pick your favorite, and be happy as a clam with them.

 

[Slater]

At higher volumes the CM5 do sound more balanced. I like the ZS5v2 at low volume, but the CM5 at low volume doesn't really come alive.

Ok, I hate subjective words so you got me there. Let's put it into comparison with some pics. I was wrong about the ZS3, I think because of the midbass hump it appears to have less sub bass.

Disclaimer: Only did these for comparison, my imm6 cal file is loaded but I have not done any other compensation. I really should fire up a laptop with Arta instead of my Samsung S3.

Graph 1 (White = ZS3 foam removed vs purple = Uiisii CM5) Graph 2 (White=UiiSii CM5 vs Purple= ZS5v2)

Awesome graphs!

Pretty consistent with how I hear them. Nice to see all 3 compared.

 

[khighly]

That's what I was just going to say. But @khighly said she's "noticed this on serveral KZ IEM's", which would be very odd if numerous cables were 1. wired incorrectly or 2. plugged in wrong.

Like @DocHoliday, I'm definitely going to be looking into this with interest as well.

@khighly, you mentioned an EDM song with whip as an example of this anomaly. Would you mind telling us the artist/title so I can check it on my gear?

Jinsang - Genesis is the song I first noticed this anomaly quite a few months ago.

Au5 - Metronic is the one I was talking about an hour ago.

 

[Slater]

So I wanted to post a follow up to the recent ZS5 v2/ZS6 mods where Russian members (@WalterTorino and @HraD2) are making the nozzle artificially smaller in diameter via foam tip mods.

• https://www.head-fi.org/threads/kno...essions-thread.698148/page-1831#post-14002591
• https://www.head-fi.org/threads/kno...essions-thread.698148/page-1833#post-14003150

I did some more ZS6 testing tonight, and came up with some alternative methods for those interested in trying this out.

In a nutshell the mods aim to increase sub-bass and decrease the spikey treble of the ZS6 (and ZS5 v2).

The Russian mods both involve foam tips, and they are both fairly difficult to achieve because it takes an incredible amount of work to stretch 3mm foam tips on the 5mm nozzle (and in the 2nd link, to stretch tips onto the 5mm nozzle AND spare silicone sleeve.

Also, if you look at this photo, you'll notice that once stretched over the extra silicone sleeve, the OD of the foam tip gets stretched MUCH larger than before. This may affect the ear canal fitment, seal, and comfort level:

I wanted to come up with a few alternate mods that ended up with the same goal, but that could be used with any tip (and still retain the ease of fitting any tip on without stretching it out).

I came up with 2 slightly different mods, that ended up doing basically the same thing (bumping sub-bass and reducing the treble spike). Both of the mods were made to 100% stock ZS6, right out of the factory fresh box, using the stock Starline tips. No BA mods, such as plugging BA drivers or stuffing them with foam.

Mod #1:

I played around with multiple iterations of teabag mesh and desiccant packet material, and I didn't really like how they veiled the sound. A few even reduced the treble energy so much it wasn't even enjoyable (all of the life got sucked out of the IEM).

What I settled on was just sticking a nylon mesh screen on top of the stock mesh. I have yet to find a source to buy brand new nylon screens, so I save them when I remove them from other IEMs. I don't remember where this particular one came from, but it is basically identical to the red one KZ uses on a ton of IEMs (EDR1, EDR2, ZS3, etc etc). It's very simple, just peel and stick, takes 10 seconds, and the mod is 100% reversible.

Once done, reinstall whatever tips you want and you're ready to go. Because these mods reduce the treble spike, I didn't have to use foam tips to reduce the treble spike. I could finally ditch the foam tips and use silicone tips (my favorite are Starline tips).

Here's what it looks like (click for larger view):

ZS6 nozzle mod (nylon mesh on top of stock mesh)


Mod #2:

The inspiration for this idea came from what KZ did on the ZS1 v1, where they inserted a small diameter brass ring in the nozzle to artificially narrow the diameter. This is one of the reasons why the ZS1 v1 is the "basshead king" of the KZ lineup. Check it out:



To duplicate this I used stainless steel DIN125-1A M2 (ie 2mm) washers. They fit the ZS6 nozzle perfectly, and match the dimensions of the ZS1 v1 brass nozzle. The washers were bought from Grainger, and cost $0.40 for a package of (50) washers - yes, you read that right - $0.008 per washer LOL. The Grainger part # is 22UH25. There was no shipping cost because I picked them up from my local Grainger store. You don't need a business account to order stuff from Grainger - just tell them it's a "will call taxable purchase" that you'll be paying cash for when you pick it up.

To install them, you remove the stock mesh with a sewing needle. Then you use tweezers to drop 1 washer into each nozzle. Be prepared to lose a few washers into the nether regions of your house - they are ridiculously small (but at $0.008 each it really doesn't matter). Anyways, there is a recessed lip on the ZS6 nozzle that allows the washer to fit right down into the nozzle. You affix the washer in place with a few micro drops of epoxy or LaserBond UV glue (applied with the sewing needle around the EDGE of the nozzle and washer seam, not UNDER the washer).

Once it's dry, reinstall whatever tips you want and you're ready to go. Because these mods reduce the treble spike, I didn't have to use foam tips to reduce the treble spike. I could finally ditch the foam tips and use silicone tips (my favorite are Starline tips).

You'll need to be a little careful with this mod, as there is no mesh to prevent earwax and debris from falling into the nozzle. However, the hole in the center is very small, and the edges of the washer will act like a block to catch debris before it gets into the hole in the center. This is exactly like the ZS1 v1 was, and that IEM had no issue with earwax and debris falling into the nozzle hole.

Here's photos of the washers and the mod (click for larger views):

Specs of the stainless washers:


The modded nozzle:


Modded nozzle vs stock nozzle:


As far as sound, both mods really do make a definite difference if you are looking for 1. More sub-bass punch, and 2. Less spikey treble. They both still allow plenty of treble brightness; they just knock down that peaky spike. Note that neither mod eliminates the cymbal splashiness/sibilance on some tracks, but it does dull it down slightly.

If you are looking for the maximum bump in sub-bass however, go with the 2nd mod, as it does bump it more than the 1st mod, as well as preserving clarity.

Or you can just pick whichever one is easiest/cheapest or whichever one you have the materials for. They are both reversible in case you don't like the sound changes, so I encourage you to try both methods and see which one you like more.

 

[Makahl]

Awesome! I just got a pair of ZS6 yesterday and I easily solved this problem of "cymbal splashiness/sibilance". I just cut out a small strip of 3M micropore and place it over the nozzle before I mounted the tip (it's important to target on the center to tame the BAs).

(btw thanks slater for the high-res pic)

IEMs, in general, are a bit tricky to me. I just created my own SYMBIO BY MANDARINES ear tips now using 3M earplugs foam + leather belt hole puncher and punch the foam away so just placing it inside the eartip to finish. Wow, what a world of difference regarding bass and isolation compared to stock. If you think this is IEM has a weak sub-bass you should mod your tip and give it a try.

You'll get something really similar to this: